Beaver Based Restoration

We include shrubs and tree species that provide good forage and dam construction materials in our riparian planting mix. Intentionally providing trees utilized by beavers helps support existing beaver populations and encourage beaver colonization in restored habitats.

The primary species included for beaver habitat improvement include willow, vine maple, black cottonwood and alder (Oregon ash has historically also been a key species, but with the arrival of the Emerald Ash Borer in Oregon we are no longer including ash in our plantings).

In combination with planting beaver-centric species, the MRWC protects key individual trees to allow them to establish in restoration sites before releasing them to beavers. This protection involves a chicken-wire cage supported on two bamboo poles, a design that prevents beavers from reaching the seedling trunk. This ensures the development of healthy and diverse riparian ecosystems.

Recently, we installed three beaver dam analogs (BDA) in Devitt Creek. This installation was part of a larger project that included fish passage improvements, large woody debris placement, and riparian enhancement.

We installed 6″ – 8″ untreated posts across the stream’s floodplain, buried the posts at least 6′ deep and cut them to an elevation of 1′ above the existing floodplain terrace. These posts were then woven with conifer limbs to begin the process of retaining woody debris and low floodplain terrace inundation to encourage beavers to colonize the reach.

A multi-year monitoring project of numerous BDAs installed in the Nehalem watershed found improvements in hydrological conditions. The beavers also began building dams of their own, sometimes using the BDAs as a foundation!

The Mid-Willamette Beaver Partnership (MWBP) is a multi-basin group of partners that is exploring where and how beaver-based restoration would make the most sense – both ecologically and sociologically.

The MWBP seeks to expand the ecological and social benefits that beaver habitats provide while mitigating the potential negative impacts beaver behavior can cause.

The MWBP includes the Bonneville Environmental Foundation (BEF); the Luckiamute (LWC), Marys River (MRWC), North Santiam (NSWC), South Santiam (SSWC) and Calapooia (CWC) Watershed Councils; the Confederated Tribes of Grand Ronde (CTGR) Natural Resources Department; and the Confederated Tribes of Siletz Indians (CTSI) Natural Resources Department.